Perhaps West read my opinion in my expressive eyes, for he fished a newspaper clipping out of a briefcase at his feet and passed it over to me. "Here!" he said, "Just look at that!"

I cannot say that it much rewarded close study. It was a three-paragraph item from some local newspaper. The headline read "A Dim Rumble" and the dateline was East Fishkill, New York. It was an account to the effect that local residents had complained to the police department of a dim rumble that left them uneasy and caused much disturbance among the cat and dog population of the town. The police had dismissed it as the sound of a distant thunderstorm, though the weather department heatedly denied that there had been any that day anywhere in the region.

"What do you think of that?" asked West.

"Might it have been a mass epidemic of indigestion?"

He sneered as though the suggestion were beneath contempt, though no one who has ever experienced indigestion would consider it that. Beneath the diaphragm, perhaps.

He said, "I have similar news items from papers in Liverpool, England; Bogota, Colombia; Milan, Italy; Rangoon, Burma; and perhaps half a hundred other places the world over. I collected them. All speak of a pervasive dim rumble that created fear and uneasiness and drove animals frantic, and all were reported within a two-day period."

"A single world-wide event," I said.

"Exactly! Indigestion, indeed." He frowned at me, sipped at his drink, then tapped his chest. "The Lord has placed a weapon in my hand, and I must learn to use it."

"What weapon is this?" I asked.

He didn't answer directly. "I found the cave quite by accident," he said, "something I welcome, for any cave whose opening advertises itself too openly is common property and has been host to thousands. Show me an opening narrow and hidden, one that is overgrown with vegetation, obscured by fallen rocks, veiled by a waterfall, precariously placed in an all but inaccessible spot, and I will show you a virgin cave worthy of inspection. You say you know nothing of speleology?"